Major League Baseball is investigating Yankees pitcher Ivan Nova and minor league hurler Wilkin De La Rosa for allegedly injecting each other with B-12 shots last season when they were teammates in Trenton (Double-A), The Post has learned.

Though B-12 isn’t on the list of baseball’s banned substances, only licensed physicians are allowed to inject medication. And MLB wants to make sure that the shots were indeed B-12.

Yankees GM Brian Cashman said he was unaware of the investigation, and MLB spokesman Pat Courtney said, “We don’t discuss the work of our investigative group.’’